Santander AT1 No-Call (2019) — When Convention Broke

AT1 (Additional Tier 1) bonds are perpetual — no maturity date. However, issuers typically hold a call option to redeem the bonds at the first call date, usually five years after issuance. This is a right, not an obligation.

Yet from the early 2010s, a market convention crystallized: "banks will always exercise the call on the first call date." This convention formed for several reasons:

1. Reputational risk: not calling was thought to make future capital raising more difficult 2. Economic logic: in declining rate environments, calling expensive old bonds and re-issuing at lower rates reduces interest costs 3. Investor expectation: investors effectively traded AT1s "like 5-year bonds" — perpetual instruments assumed to be redeemed at the call date

This convention became so entrenched that many investors treated the call date as the effective maturity, calculating yields as Yield to Call (YTC) rather than to perpetuity. Extension risk — the risk of call non-exercise and resulting term extension — existed in theory but was considered practically non-existent.

On February 12, 2019, that premise collapsed.

In 2014, Santander issued €1.5 billion in AT1 bonds at a 6.25% coupon, with a first call option in February 2019. If not called, the coupon would reset to a 5-year swap rate plus spread.

In February 2019, European rates were low. The 5-year EUR swap rate was approximately -0.05% to 0.1%. Under Santander's AT1 contract, the coupon would reset to the swap rate plus an initial spread (~5.36%) — resulting in approximately 5.4–5.5%.

The key calculation: to make calling the bond economically rational, a new AT1 issuance would need to be cheaper than 6.25%. In February 2019, new AT1 issuance in the market was pricing at approximately 6%+.

Post-reset coupon: ~5.4% Expected new issuance coupon: ~6%+

Conclusion: not calling is economically cheaper. Santander acted on this calculation.

This was entirely legal, and contractually explicit. But markets were shocked.

Immediately after Santander's no-call announcement, the AT1 market sold off sharply.

Santander's 6.25% AT1 bond price fell from approximately 101–102 to below 98 — the bond had been priced on a call basis, and now needed to be repriced on an extension basis.

The larger problem was contagion: other banks' AT1 bonds also fell. The question spread through markets: "Which other bank might skip its next call date?"

Extension risk — the risk that a call is not exercised and the investment term extends — had moved from theory to reality. The convention of trading perpetual bonds like 5-year instruments was now subject to fundamental re-examination.

Core lessons AT1 investors absorbed: 1. The call date is not a maturity date 2. Issuers may rationally not call when it's economically suboptimal 3. Reset coupon levels can make extension advantageous for the issuer 4. AT1 analysis must explicitly calculate reset mechanisms and call exercise incentives

After Santander's no-call, structural changes rippled through the AT1 market.

Pricing methodology shift: Investors began calculating both Yield to Maturity (YTM, assuming extension) and Yield to Call (YTC). Making investment decisions based on the lower of the two — Yield to Worst (YTW) — became standard practice.

Deeper reset spread analysis: Frameworks developed for estimating call exercise probability by analyzing expected reset coupon levels versus current new issuance rates.

Issuance structure changes: Some issuers began structuring AT1s with stronger call incentives — step-up coupons (coupons that increase sharply after the call date) as a de facto commitment mechanism.

Subsequent call skips by other banks occurred but were no longer treated as shocks — Santander 2019 had normalized "call skipping is possible" as market convention.

The most important lesson from Santander's AT1 no-call is simple: market convention is not contractual obligation.

Investors had effectively priced in "banks always call at first opportunity" as if it were a contractual term. But the contract only said: "the issuer may call, at its option."

Convention holds only as long as economic incentives align with it. When the rate environment changes — when the reset coupon falls below new issuance rates — the issuer's rational decision changes accordingly.

This is not an AT1-specific issue. Many market 'conventions' depend not on contracts but on economic incentives. When incentives change, conventions change. Investors must always distinguish between contractual rights (what the contract says) and economic behavior (what the issuer will rationally do).